Fountain pen holder



April-30, 1940.

G. K. Bon

FOUNTAIN PEN HOLDER Filled Dec. '15 1938 Patented A'p 30. 1940 UNITED STATES FOUNTAIN PEN HOLDER Gabor Kroly Bod, Budapest, Hungary Application December 15, 1938, Serial No. 245,955

In Hungary August 8, 1938 The fountain pen type capable of holding the greatest volume of ink as compared to its size is the one Vin which .the ink well is bounded by a piston axially displaceable along a rotatable guide `screw spindle extending along the whole 1 ength of the ink well. The possibility of dis- ;.\.acing the piston to the extent in which the supply of ink diminishes enables the quantity of air contained in the ink space to be limited to such an extent as to prevent the heat expansion of the said air crowding out more ink than necessary. Devices of this type have, however, notwithstanding their great advantages, not been adapted for practical use, as tight packing between the piston and the guide spindle, which is an indispensable condition of the suitability of the pen holder for practical use, could not be permanently assured.

The invention isbased on the discovery that the cross-section of the guide spindle passing through the `piston composed of resilient material like soft rubber should be circular and as small as possible and that at least one complete turn of' thread should be embedded into the material of the piston, notably as far as possible without tension. This purpose is achieved according to the present invention which is characterized in that the guide spindle of the piston consists o f a spiral bent from a wire of substantially circular cross-section one end of which is fixed into the closing cap journalled in a rotatable manner and closing the ink reservoir While its other end isv a free, careless cylindrical spiral, whereas the piston composed of resilient material like soft rubber is fitted with an extension having a diameter smaller than the piston and enclosing together with the piston at least one complete turn of thread of the guide spiral.

In contradistinction thereto, the known types of fountain pen holders of this kind there have v been employed guide spindles tted with cores, around the core of which the guide spiral was wound in such a manner that the cross section perpendicular to the spiral turns of the guide i spindle was non-circular. Now4 on the other hand the rubber-like piston material owing to its resiliency can permanently assure good packing only if a deformation equal in all directions is set up, namely, if the cross-section of the guide l spindle is of the same dimension in all directions, i. e., if the spindle is of circular cross-section. Another drawback or similar devices employed rrp to now was that the guide spindle was journalled at both ends. Now, owing to the fact that 5 the device was of a knematically over-defined kind, it has not been possible to assure that the axis of rotation of the guide spindleshould along a. so great an amount of wear of the piston at the places in contact with the guide spindle as to cause close packing to cease. In the devices employed up to now the packing between the piston and the guide spindle was also defective for the further reason that the length of the piston only extended `to a fraction of the height of turn of the guide spindle and that accordingly the length of packing was too small. It is not possible to increase the length of packing by increasing the length of the piston, because the increased rigidity of a piston of greater length will, particularly in the case of a guide spindle journalled at both ends, substantially promote wear between the piston and the guide spindle and thus good packing will soon cease on'the 25 longer 4piston also. This drawback is eliminated A by the invention in consequence of the design referred to above by increasing the length of packing by an extension having a diameter smaller than that of the piston and surrounding the guide spindle the said extension not being supported on the wall of the ink reservoir so that notwithstanding the increase of the length of packing the rigidity of the piston is not increased. Nor does the extension owing to its small diameter 4appreciably diminish the capacity of the ink reservoir. Another advantage of the extension is that by'means of a clamping ring drawn on it the durability of good packing between the piston body and the guide spindle can be in- 40 creased.

In view of the fact that the fountain pen device in question makes it possible, in the manner y mentioned above, to keep the quantity of air,

which has `penetrated into the ink reservoir in place of the ink consumed by writing, below a certain limit, independently of the diminution of the quantity of ink, it is not necessary to construct the barrel of the pen serving as an inkl reservoir of thick-walled material having good heat insulating properties. It is now possible to make it of thin-walled metal tubing, whereby with the same external diameter the capacity of the ink reservoir can be substantially increased. However, the usual connection with the end 6b of the spiral 6 which serves as the guldit is only fixed by friction or cementing or possibly by both, whereas on the closing cap carry.- ing the guide spiral a metal sleeve clamped into the free end of the ink reservoir and fixed by means of friction is journalled in a rotatable manner. i,

The accompanying drawing shows by way of lexample one embodimentof the invention.

Fig. 1 is a longitudinal section of the fountain pen holder according to the invention.

Fig. 2 is a. longitudinal section drawn to a larger scale of the piston.

Fig. 3 is a longitudinal section drawn to a larger scale of the nib and of the ink spoon.

Fig. 4 is a cross section along line 4 4 olf Fig. 3.Y

I The fountain pen holder body consists of the barrel I which serves as an ink reservoir and is made of a preferably thin-walled metal tube I (Fig. 1) along the length of which the piston 22 is displaceably inserted. Into. the lower end Ia of the barrel I the metal sleeve 2 is clamped in closely so that the metal sleeve 2 is fixed in the end of the barrel I-by friction. In the metal sleeve 2 the 'cap 3 is supported in a rotatable manner, the flange 5 of the sleeve 2 engaging with a groove 4 of the said cap. The cap 3-is fixed on the lower end 6a of the spiral 6 which is wound from a thin wire having a substantially circular cross section and which should preferably be acid-orl ink-proof. lFor this purpose the cap 3 `is preferably made of synthetic material and pressed into the end ofthe spiral 6. The upper ing spindle of the piston' 22, is free. 'I'he piston which is reciprocated by means of the guide spiral 6 is made of resilient material, as soft rubber, preferably of polymeric compounds and is tted with an extension 8 having a diameter smaller than that of the piston 22 and having such a length that, together with the piston, this extension' should surround at least one, but preferably one and a half turns'of the guide spiral 6. The extension 8 should preferably be slightly l tapered and the clamping ring 9 which is slightly tapered likewise is drawn on the said extension. The head piece II holding the pen I0 is likewise fixed by meansof friction or cementing into the upper end Ib of the barrel I by means of the extension-I4 of the said head piece.

The piston 22 is prevented from rotating by friction with the barrel I, so that, when the cap 3 is rotated, the guide spiral 6 will displace the piston 22 in the one or in the other vertical direction, according to the sense of rotation. During its displacement the piston 22 will be able, by means of the dellection of the guide spiral 6 to compensate for the small deviations existing between the gegimetrical axis of the guide spiral and of y{the piston on the one handV and between the axis of rotation of the guide spiral on the other hand.

For the purpose of filling the pen holder the closing cap 3 is rotated in such a sense as to ensure that the piston 22 should be displaced to-l wards the free end 6b of the guide spiral; then the nib II'I is d ipped into ink and the piston 22 is caused to approach the closing cap 3 by rotating this cap 3 in the opposite direction. During this process the ink reservoir 'l in front of the piston will become filled with ink. When during use of the pen the quantity of air has become excessively increased in the ink reservoir 'I owing to the consumption of ink, the pen holder is held with its nib upwards and the piston 22 is moved in the upward direction by rotating the cap 3, whereby the quantity of air contained in the ink reservoir 1 is partly or entirely driven out.

.In order to prevent that during this process the air flowing out through the air opening I2 provided at the end of the slot of the nib draws bubbles of ink, a tubular extension I3 joins on to the edge, of the opening I2 of the nib, which extension breaks the approximatelysmooth surface required for the formation of bubble at the flange of the air opening.`

' What I claim is:

1."A fountain pen, comprising a barrel, a rotatable cap at the base of the barrel provided Ywith a guide spiral extending along the length of the ink reservoir and being bent from a wire of circular cross section, said wire being fixed with one end into the closing cap, said cap being journalled to the barrel in a rotatable manner,

tatable cap at the basev of the barrel provided,

with a guide spiral extending along the length of the ink reservoir and being bent from a. wire of circular cross section, said wire being 'fixed with one end into the closingcap, said cap being journalled to the barrel in a rotatable manner,

the other end of said wire forming a free coreless cylindrical spiral, a piston in said barrel being y reciprocated by said spiral, said piston consisting of resilient material, such as soft rubber, and

fitted with a tapered extension having a diameterk smaller than the base of said piston, said extension being surrounded by a tapered clamping ring and together with the piston enclosing at least one complete turn of the thread of said guide spiral.

3. A fountain pen according to claim 1, in which the barrel constituting the ink reservoir of the fountain pen is a metal tube, into which the ends of the head piece holding the nib, and the sleeve in which the closing cap holding the guide spiral is rotatably journalled, are fastened by friction. l

4 4. A fountain pen according to claim 1, in which the barrel constituting the inkreservoir of the fountain pen is a metal tube, into which the ends of the head piece holding the nib, and the sleeve in which the closing cap holding the guide spiral is rotatably journalled, are fastened by cementing.

5. A fountain pen according to claim 1 having a nib with a tubular extension joining on tothe edge of the air opening at the end of the slot of said nib.

G. KAROLY BODO. 

